Length-weight relationships and condition factors of Alestes baremoze, Brycinus nurse and Schilbe intermedius from the lower reaches of white volta river (Yapei), Ghana

摘要

A study to assess the length-weight relationships and the condition factors of 3 abundant and commercial fish species namely?Alestes baremoze,??Brycinus nurse?and?Schilbe intermediusin the lower reaches of the White Volta River (Yapei) was conducted from October 2011 to March 2012. Using W = aLb, the length-weight relationships of the species were calculated. Condition factors of the species were obtained using the formula: W*100/Lb. A total of 284?A. baremoze?were measured with total mid length size range of 10.5 to 44.5 cm. A total of 197?B. nurse?were measured and ranged from 6.5 to 27.5 cm total mid-length whereas 175 of?S. intermedius?were measured and had total mid length size range of 8.5 to 26.5 cm. The slope?bof the length-weight relationships of the 3 species were within the acceptable range of 2.5 to 3.5 and can be used to approximate the weight for the 3 species in the lower reaches of the White Volta River. The condition factors variation of?A. baremoze?and?B.?nurse?showed a pronounced change in December 2011, when the surface water temperature was lowest.?S.intermedius?had no significant changes in the condition factors over the study period.